The present application relates to a battery, an electrode, a battery pack, an electronic device, an electric vehicle, a power storage device, and a power system.
Expectations and the market for a battery using a non-aqueous electrolyte solution, in particular, a lithium ion secondary battery, are growing increasingly because such a battery can have a higher energy density than a lead-acid battery or a nickel-cadmium battery, which is an aqueous-based electrolyte solution secondary battery according to the related art. Specifically, since characteristics of the lithium ion secondary battery, such as lightness and the high energy density, can be suitably applied to electric cars and hybrid electric cars, the battery has been extensively studied in recent years in order to obtain larger sizes and higher outputs.
In particular, in order to use a cell with higher output, a structure has been proposed in which a mixture layer is positioned on the left and right sides of a positive electrode lead. Thus, the cell resistance can be lowered and a cell with higher output can be obtained (see JP 2004-311282A and JPH 10-241696A).
In addition, as for the secondary battery, a variety of techniques have been proposed regarding bonding of an electrode body, a lead, and a current collector. For example, in JP 2010-212086A, a technique to suppress a break of the current collector is proposed (see JP 2010-212086A). For example, in JP 2009-134971A, an ultrasonic welding method of a positive electrode current collector and a tab is proposed in order to provide a lithium ion battery with excellent mechanical strength and shock resistance (see JP 2009-134971A).